In a nutshell
This article reviewed the treatment options for chronic myeloid leukemia (CML) in blast crisis.
Some background
Patients in CML blast crisis have a high percentage (more than 30%) of blast cells (leukemia cells) in the blood or bone marrow. The patient may also experience symptoms such as night sweats, fever, bone pain, or anemia (low levels of red blood cells). Blast crisis has become much rarer due to treatment with tyrosine kinase inhibitors (TKIs, such as imatinib). The reason for blast crisis is not well understood. It has been shown, however, that 80% of blast crisis patients have additional mutations (permanent changes) in the BCR-ABL gene that leads to CML. The optimal treatment for blast crisis is unclear.
Methods & findings
This study reviewed treatment options and recommendations for CML in blast crisis.
If the patient has not been treated with a TKI, a TKI such as imatinib should be tried, followed by stem cell transplantation as quickly as possible. Studies have shown cytogenic response rates (CRR; a decrease in the abnormal chromosome involved in CML) in 12%-17% after treatment with imatinib. One-year survival rates were 22%-36%.
If the patient progresses after imatinib, other TKIs can be tried. Dasatinib (Sprycel) has been shown to lead to CRRs of 35%-56%. CRRs with nilotinib (Tasigna) range from 38%-52%.
If there is disease progression after multiple TKIs, chemotherapy may be an option.
Stem cell transplantation from a closely matched donor is an important treatment option, and the best chance of cure. One study including 25 blast crisis patients (already treated with imatinib) showed a 59% 3-year survival rate after transplantation. TKI therapy should be continued following transplantation.
Trials are looking at new treatment options, including imatinib in combination with chemotherapies, as well as new TKIs.
The bottom line
This study reviewed treatment options for patients CML blast crisis.
The fine print
Prevention of blast crisis by early elimination of BCR-ABL is recommended – the best way is to avoid getting to blast crisis is by good treatment in the chronic phase.
